You can use this property to customize the way numbers, dates, times, and text are displayed and printed.
For example, if you've created a Price field, you can set its Format property to "Currency". If the field value is set to "4321.678", it would be rendered as $4,321.68.
You can use this property to format numbers (including currency and percentage values), dates, boolean values, and strings.
The syntax for the format string is the same as used with the .NET System.String.Format(System.String,System.Object) method.